Conventional vehicle braking systems employ friction elements to provide resistance to wheel rotation. The friction elements in such conventional braking systems convert the kinetic energy of a moving vehicle to heat, which then escapes to the atmosphere.
Regenerative braking systems have been proposed to recover the kinetic energy of the vehicle and store the energy in an energy storage device for use during vehicle acceleration or other vehicle functions. Energy storage devices proposed for regenerative braking include electrochemical batteries, ultracapacitors, and flywheels.